3 days in Barcelona

I like to choose what interests me from the AT A GLANCE section of this website.
https://www.ricksteves.com/europe/spain/barcelona

Look up "3 days Barcelona" on YouTube and there's a ton of videos with suggested itineraries.

https://www.google.com/search?q=can+you+plan+three+days+in+Barcelona+for+me.+I+just+want+to+see+the+highlights&rlz=1C1VDKB_enUS1116US1116&oq=can+you+plan+three+days+in+Barcelona+for+me.+I+just+want+to+see+the+highlights&gs_lcrp=EgZjaHJvbWUyBggAEEUYOdIBCTEzNDUxajBqN6gCALACAA&sourceid=chrome&source=chrome.ob&ie=UTF-8

Try AI. With only 3 days and so many big attractions in Barcelona, most 3 day itineraries look very similar.

FWIW, IMO, the best paid attraction was the Palau of Catalan Music (especially if you have Gaudi overload) and the best free attraction was the food court on the top floor if the El Corte Ingles (awesome views). Good luck.